Overheating BlackBerrys not big in Japan

NTT DOCOMO, which sells the handheld, has said that 30 customers have complained of overheating on the product, specifically around the keyboard during recharging.

Given that only around 4,000 of the handsets has been sold so far this accounts for nearly one per cent of the user base.

Canadian firm RIM, which manufactures the device, has said that it is investigating the issue but preliminary reports suggest that it is not related to the battery.

It notes that none of the devices have harmed any customers or caught fire.

"This issue appears to be specifically limited to the BlackBerry Bold devices sold in Japan since last week and sales of BlackBerry Bold devices in other countries are unaffected by this matter," it said in a statement.

The Japanese model differs in some ways for BlackBerry Bolds in other markets. It is quad-band rather than tri-band and has a different keyboard to show Japanese characters. A model without a camera is also on offer.

The move is bad news for RIM, which has had difficulty in breaking into the Japanese market, compared to its success in the US and Europe.